The pixel intervals a band or point scale assigns to its categories.
Marks are not always drawn flush to their band — Plot insets rect and cell
marks by half a pixel, and a dot sits at the band's midpoint — so matching a
pixel to a category by equality fails. Intervals let
valueAtPixel ask which band contains a point instead.
The pixel intervals a band or point scale assigns to its categories.
Marks are not always drawn flush to their band — Plot insets rect and cell marks by half a pixel, and a dot sits at the band's midpoint — so matching a pixel to a category by equality fails. Intervals let valueAtPixel ask which band contains a point instead.